Azo dyestuffs



Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE WINFRID HEN'I'RICH,OF WIESDORFON-THE-RHINE, GERMANY, ASSIGNOR T0 GEllT- ERAL ANILINE WORKS,INC, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE AZO DYESTUFFS NoDrawing. Application filed May 9, 1927, Serial No. 180,139, and inGermany May 19, 1926'.

The present invention relates to new acidmono-azo dyestuffs, which maybe obtained by coupling a diazo compound of a2.4.6-trinitro-l-aminobenzene or its substitution products with asulphonic acid of the N-alkyl-, N-aryl,- or N-aralkyl-anilines, theirhomologues or substitution products, and which may be represented by thegeneral formula:

wherein Xstands for hydrogen or alkyl, one

Y for alkyl, aryl or aralkyl, the other Y for hydrogen, alkyl, aryl oraralkyl, and R may be substituted or not.

My new dyestuffs are soluble in water, very stable against heat, fast toacids or dilute alkalis, and possess the Valuable property of dyeingdirectly on acidyl celluloses or their conversion products. The dyeingson acetate silk are very fast to washing and to water and of outstandingfastness to light.

Example 228 parts by weight of 2.4.6-trinitro-1- aminobenzene areintroduced at ordinary temperature into a quantity of nitrosyl sulphuricacid, prepared in the customary manner from 1000 volumes of sulphuricacid monohydrate and 70 parts by weight of dry 100% sodium nitrite. Thewhole is heated with stirring to about 40 C. with effective exclusion ofmoisture until a test portion poured on ice no longer shows the presenceof nitrous acid.

A solution of 305 parts by weight of N-4-sulphobenzyl-3-toluidineN-ethylin about 3000 volumes of sulphuric acid monohyd'rate is thenintroduced at 0 C. and stirring is continued for some time. On causingthe yellowish solution thus obtained to drop with brisk stirring slowlyinto a large quanity of ice-water; which advantageously contains alittle sodium sulphate, the reddish blue dyestuff acid is immediatelyprecipitated in a state, allowing easy filtration. The followingformularepresents the new dyestuf'f When the reaction is complete the dyestufl'is soon filtered, washed with a little water and converted into thesodium or ammonium salt (by means of sodium carbonate or ammonia) in thecustomary manner at slightly increased temperature. After drying at C.the dyestuif represents a powder about with a coppery lustre and iseasily soluble in water with a reddish blue coloration soluble inconcentrated sulphuric acid with orange tained which dyes acetate silkin strong bluish 0 violet shades, possessing the same fastnessproperties. The employment of N-4-sulphobenzyl-Q-toluidine,N-benzyl-aniline-Q-sulphonic acid, N-dimethylaniline-B sulphonic acid ora diphenyl amino mono sulphonic acid as coupling components leads to theproduction of dyestuffs of similar properties. Likewise the applicationof 3-1nethyl-2Al5-trinitro l-aminobenzene instead of the amide of picricacid produces analogous results.

I claim:

1. New lnono-azo dyestuffs of the formula OzN N=N- R N SOIIH \Y X N02wherein R and R may be substituted or Y not and Y stands for hydrogen oran alkyl residue, which are as sodium salts dark powders, soluble inwater with violet to blue color, being very stable against heat, fast toacids or dilute alkalis, dyeing acetate silk violet to blue shades ofexcellent fastness to washing, to water and to light.

3. As new products azo dyestuffs of the general formula shades ofexcellent fastness to washing, to water and to light.

4:. A new dyestuif of the formula which is in a dry state a dark powderwith a coppery lustre, easily soluble in water with a reddish bluecoloration soluble in concentrated sulphuric acid with orange red colordyeing acetate silk in marine blue shades fast to washing, to water andto light, dyeing wool in an acid bath in bluish black shades.

In testimony whereof I have hereunto set my hand.

W INFRID HENTRICH.

wherein R and R may be substituted or not and Y stands for an alkylresidue, which are as sodium salts dark powders, soluble in 'ater withviolet to blue color, being very stableagainst heat, fast to acids ordilute alkahs, dyeing acetate silk violet toblue 1 Certificate ofCorrection Patent No. 1,732,512 Granted October 22, 1929, to

' WINFRID HENTRICH.

It is hereby certified that error appears in the printed specificationof the abovenurnbered patent requiring correction as followsrPage 2,line 70, strike out the formula and insert instead and that the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of December, A. D. 1929.

'[sEAL] M. J; MOORE, Acting Gammissioner of Patents.

